<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="#" method="get" autocomplete="on">
<label for="username">用户名:</label>
    <!--value="张三"-->
<input type="text" id="username" name="username"  placeholder="请在此处输入用户名" required/>
    <label for="username">用户名:</label>
    <!--value="张三"-->
    <input type="text" id="pass" name="username"  placeholder="请在此处输入用户名" required/>
<button type="submit">提交</button>
<button type="reset">重置</button>
<button type="button">按钮</button>
    </form>
</body>
</html>